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  Subjects -> VETERINARY SCIENCE (Total: 213 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brasilica     Open Access  
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 2)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 6)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 11)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 15)
African Journal of Wildlife Research     Full-text available via subscription  
Alexandria Journal of Veterinary Sciences     Open Access   (Followers: 1)
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 11)
American Journal of Primatology     Hybrid Journal   (Followers: 7)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 24)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 4)
Animal Behaviour     Hybrid Journal   (Followers: 131)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6)
Animal Health Research Reviews     Hybrid Journal   (Followers: 5)
Animal Nutrition     Open Access   (Followers: 7)
Animal Reproduction     Open Access  
Animal Reproduction Science     Hybrid Journal   (Followers: 6)
Animals     Open Access   (Followers: 6)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 8)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 7)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Arquivos de Ciências Veterinárias e Zoologia da UNIPAR     Open Access  
Ars Veterinaria     Open Access  
Asian Journal of Medical and Biological Research     Open Access  
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 2)
Australian Veterinary Journal     Hybrid Journal   (Followers: 15)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 5)
Avian Diseases Digest     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 3)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 1)
Bangladesh Veterinarian     Open Access   (Followers: 1)
BMC Veterinary Research     Open Access   (Followers: 10)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Bulletin of Animal Health and Production in Africa     Full-text available via subscription   (Followers: 1)
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 8)
Case Reports in Veterinary Medicine     Open Access   (Followers: 6)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access  
Companion Animal     Full-text available via subscription   (Followers: 5)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 2)
Equine Health     Full-text available via subscription   (Followers: 1)
Equine Veterinary Education     Hybrid Journal   (Followers: 8)
Equine Veterinary Journal     Hybrid Journal   (Followers: 12)
Ethiopian Veterinary Journal     Open Access   (Followers: 4)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Frontiers in Veterinary Science     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 2)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 6)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 3)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 3)
Indonesia Medicus Veterinus     Open Access  
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 5)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 7)
InVet     Open Access  
Iranian Journal of Applied Animal Science     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 5)
İstanbul Üniversitesi Veteriner Fakültesi Dergisi     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 6)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 11)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 2)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 6)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 10)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 4)
Journal of Experimental and Applied Animal Sciences     Open Access  
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 3)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 11)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 29)
Journal of the Selva Andina Research Society     Open Access  
Journal of the South African Veterinary Association     Open Access   (Followers: 2)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 4)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 4)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 7)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 9)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 16)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 18)
Journal of Veterinary Medical Education     Partially Free   (Followers: 14)

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Journal Cover Veterinary Microbiology
  [SJR: 1.425]   [H-I: 84]   [8 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
   Published by Elsevier Homepage  [2801 journals]
  • IFC - Aims & Scope, EDB, Publication Information
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184




      PubDate: 2016-02-09T19:34:42Z
       
  • Two-way antigenic cross-reactivity between porcine epidemic diarrhea virus
           and porcine deltacoronavirus
    • Abstract: Publication date: Available online 9 February 2016
      Source:Veterinary Microbiology
      Author(s): Yuanmei Ma, Yu Zhang, Xueya Liang, Michael Oglesbee, Steven Krakowka, Andrew Neihaus, Guiping Wang, Aiqing Jia, Houhui Song, Jianrong Li
      Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PdCV) cause indistinguishable clinical signs and pathological changes in swine. Here we investigated the antigenic relationship between PEDV and PdCV. We provide the first evidence that conserved epitope(s) on the respective viral nucleocapsid proteins cross-react with each other although virus neutralization cross-reactivity was not observed. As a practical matter, prevention of these two very similar diseases of swine will require the development of separate virus-specific vaccine products.


      PubDate: 2016-02-09T19:34:42Z
       
  • Impact of the administration of a third-generation cephalosporin (3GC) to
           one-day-old chicks on the persistence of 3GC-resistant Escherichia coli in
           intestinal flora: An in vivo experiment
    • Abstract: Publication date: 15 March 2016
      Source:Veterinary Microbiology, Volume 185
      Author(s): Sandrine Baron, Eric Jouy, Fabrice Touzain, Stéphanie Bougeard, Emeline Larvor, Claire de Boisseson, Michel Amelot, Alassane Keita, Isabelle Kempf
      The aim of the experiment was to evaluate under controlled conditions the impact on the excretion of 3GC-resistant Escherichia coli of the injection of one-day-old chicks with ceftiofur, a third-generation cephalosporin (3GC). Three isolators containing specific-pathogen-free chicks were used. In the first one, 20 birds were injected with ceftiofur then ten of them were orally inoculated with a weak inoculum of a 3GC-resistant E. coli field isolate containing an IncI1/ST3 plasmid encoding a bla CTX-M-1 beta-lactamase. The other chicks were kept as contact birds. None of the 20 birds in the second isolator were injected with ceftiofur, but ten of them were similarly inoculated with the 3GC-resistant strain and the others kept as contact birds. A third isolator contained ten non-injected, non-inoculated chicks. Fecal samples were collected regularly over one month and the E. coli isolated on non-supplemented media were characterized by antimicrobial agar dilution, detection of selected resistance genes and determination of phylogenetic group by PCR. The titers of 3GC-resistant E. coli in individual fecal samples were evaluated by culturing on 3GC-supplemented media. Results showed that the inoculated strain rapidly and abundantly colonized the inoculated and contact birds. The ceftiofur injection resulted in significantly higher percentages of 3GC-resistant E. coli isolates among the analyzed E. coli. No transfer of the 3GC-encoding plasmid to other isolates could be evidenced. In conclusion, these results highlight the dramatic capacity of 3GC-resistant E. coli to colonize and persist in chicks, and the selecting pressure imposed by the off-label use of ceftiofur.


      PubDate: 2016-02-09T19:34:42Z
       
  • In the centre of an epidemic: Fifteen years of LA-MRSA CC398 at the
           University Hospital Münster
    • Abstract: Publication date: Available online 1 February 2016
      Source:Veterinary Microbiology
      Author(s): S. van Alen, B. Ballhausen, G. Peters, A.W. Friedrich, A. Mellmann, R. Köck, K. Becker
      Ten years after initial publications on livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in 2005, we report on the course of the LA-MRSA CC398 epidemic among patients of the University Hospital Münster. This tertiary care facility is located in the Dutch-German border region (EUREGIO), which is characterized by a high density of livestock production and is hence a hotspot for the occurrence of LA-MRSA CC398. Taking advantage of the unique opportunity to track the emergence and spread of MRSA CC398 among humans from the very beginning of the epidemic until today, a total of 6555 non-duplicate MRSA isolates from all screenings and clinical specimens cultivated within the period from 2000 to 2014 were included in the analysis. Retrospectively, the first MRSA CC398 isolate (spa type t034) was obtained from a screening specimen of a patient in 2000, which represents one of the first human-associated LA-MRSA CC398 isolates reported in Europe. After sporadic detections between 2000 and 2004, this clonal lineage accounted for 9.6% of all local MRSA in 2005; a proportion which increased to 35% in 2013 and became stable since then. Considering the period from 2000 to 2014, the group of MRSA CC398 isolates comprised a total of 45 different spa types among which t011 (48.3%), t034 (39.3%) and t108 (3.5%) were predominant and so far unreported types were found. Overall, LA-MRSA CC398 emerged rapidly during the past decade, developed enormous sublineage diversity and contributed substantially to the total burden of MRSA colonization and infection at the hospital.


      PubDate: 2016-02-09T19:34:42Z
       
  • Mechanisms of cephalosporin resistance in indicator Escherichia coli
           isolated from food animals
    • Abstract: Publication date: Available online 2 February 2016
      Source:Veterinary Microbiology
      Author(s): Anna Lalak, Dariusz Wasyl, Magdalena Zając, Magdalena Skarżyńska, Andrzej Hoszowski, Ilona Samcik, Grzegorz Woźniakowski, Krzysztof Szulowski
      Resistance to β-lactams is considered one of the major global problems and recently it became the most frequently studied topic in the area of antimicrobial resistance. The study was focused on phenotypic and genetic characterisation of commensal Escherichia coli (E. coli), including those producing cephalosporinases, isolated from gut flora of healthy slaughter animals. E. coli were cultured simultaneously on MacConkey agar (MCA) and cefotaxime supplemented MCA. The isolates were confirmed with ONPG and indol tube tests as well as PCR targeting uspA gene. Microbroth dilution method was applied for determination of Minimal Inhibitory Concentrations and interpreted according to EUCAST epidemiological cut-off values. Cephalosporin resistance phenotypes were defined by E-tests (BioMerieux) and relevant gene amplicons from selected strains were sequenced. A total of 298 E. coli isolates with cephalosporin resistance (ESC) found in 99 ones, were obtained from 318 cloacal or rectal swabs deriving from broilers, layers, turkeys, pigs and cattle. Both extended spectrum β-lactamase (ESBL) and ampC-cephalosporinase resistance phenotypes were noted in all tested animal species but cattle. At least one of the analysed genes was identified in 90 out of 99 cephalosporin-resistant isolates: bla TEM (n =44), bla CMY (n =38), bla CTX-M (n =33) and bla SHV (n =12). None of the phenotypes was identified in nine isolates. Sequencing of PCR products showed occurrence of ESBL-genes: bla CTX-M-1/-61, bla SHV-12, bla TEM-1,-52/-92,-135 and ampC-gene bla CMY-2. They were located on numerous and diverse plasmids and resistance transferability was proved by electroporation of bla SHV-12 and bla CTX-M-1/-61 located on X1 plasmids. Detection of cephalosporin resistant E. coli confirms the existence of resistance genes reservoir in farm animals and their possible spread (i.e. via IncX1 plasmids) to other bacteria including human and animal pathogens. The identified genetic background indicates on ecological aspects of selection and dissemination of cephalosporin resistance in E. coli isolated from food-producing animals rather than its potential role for public health threats.


      PubDate: 2016-02-09T19:34:42Z
       
  • Vancomycin resistant Enterococcus spp. from crows and their environment in
           metropolitan Washington State, USA: Is there a correlation between VRE
           positive crows and the environment'
    • Abstract: Publication date: Available online 3 February 2016
      Source:Veterinary Microbiology
      Author(s): Marilyn C. Roberts, David B. No, John M. Marzluff, Jack H. Delap, Robert Turner
      Vancomycin-resistant enterococci [VRE] have been isolated from municipal, hospital and agricultural wastewater, recreational beaches, wild animals, birds and food animals around the world. In this study, American crows (Corvus brachyrhynchos) from sewage treatment plants (WWTP), dairy farms, and a large roost in a restored wetland with corresponding environmental samples were cultured for VRE. A total of 245 samples [156 crows, 89 environmental] were collected and screened for acquired vanA, vanB and/or intrinsic vanC1 genes. Samples were enriched overnight in BHI supplemented with 20μg/mL aztreonam, 4μg/mL vancomycin and plated on m-Enterococcus agar media supplemented with 6μg/mL vancomycin. Selected colonies were grown on BHI media supplemented with 18μg/mL vancomycin. Of these, 24.5% of the crow and 55% the environmental/cow samples were VRE positive as defined by Enterococcus spp. able to grow on media supplemented with 18μg/mL vancomycin. A total of 122 VRE isolates, 43 crow and 79 environmental isolates were screened, identified to species level using 16S sequencing and further characterized. Four vanA E. faecium and multiple vanC1 E. gallinarum were identified from crows isolated from three sites. E. faecium vanA and E. gallinarum vanC1 along with other Enterococcus spp. carrying vanA, vanB, vanC1 were isolated from three environments. All enterococci were multidrug resistant. Crows were more likely to carry vanA E. faecium than either the cow feces or wetland waters/soils. Comparing E. gallinarum vanC1 from crows and their environment would be useful in determining whether crows share VRE strains with their environment.
      Graphical abstract image

      PubDate: 2016-02-09T19:34:42Z
       
  • Vibrio lentus protects gnotobiotic sea bass (Dicentrarchus labrax L.)
           larvae against challenge with Vibrio harveyi
    • Abstract: Publication date: Available online 4 February 2016
      Source:Veterinary Microbiology
      Author(s): M. Schaeck, L. Duchateau, W. Van den Broeck, S. Van Trappen, P. De Vos, C. Coulombet, N. Boon, F. Haesebrouck, A. Decostere
      Due to the mounting awareness of the risks associated with the use of antibiotics in aquaculture, treatment with probiotics has recently emerged as the preferred environmental-friendly prophylactic approach in marine larviculture. However, the presence of unknown and variable microbiota in fish larvae makes it impossible to disentangle the efficacy of treatment with probiotics. In this respect, the recent development of a germ-free culture model for European sea bass (Dicentrarchus labrax L.) larvae opened the door for more controlled studies on the use of probiotics. In the present study, 206 bacterial isolates, retrieved from sea bass larvae and adults, were screened in vitro for haemolytic activity, bile tolerance and antagonistic activity against six sea bass pathogens. Subsequently, the harmlessness and the protective effect of the putative probiotic candidates against the sea bass pathogen Vibrio harveyi were evaluated in vivo adopting the previously developed germ-free sea bass larval model. An equivalence trial clearly showed that no harmful effect on larval survival was elicited by all three selected probiotic candidates: Bacillus sp. LT3, Vibrio lentus and Vibrio proteolyticus. Survival of Vibrio harveyi challenged larvae treated with V. lentus was superior in comparison with the untreated challenged group, whereas this was not the case for the larvae supplemented with Bacillus sp. LT3 and V. proteolyticus. In this respect, our results unmistakably revealed the protective effect of V. lentus against vibriosis caused by V. harveyi in gnotobiotic sea bass larvae, rendering this study the first in its kind.


      PubDate: 2016-02-09T19:34:42Z
       
  • Murine immunization with CS21 pili or LngA major subunit of
           enterotoxigenic Escherichia coli (ETEC) elicits systemic and mucosal
           immune responses and inhibits ETEC gut colonization
    • Abstract: Publication date: Available online 6 February 2016
      Source:Veterinary Microbiology
      Author(s): Chengxian Zhang, Junaid Iqbal, Oscar G. Gómez-Duarte
      CS21 pili of enterotoxigenic Escherichia coli (ETEC) is one of the most prevalent ETEC colonization factors. CS21 major subunit, LngA, mediates ETEC adherence to intestinal cells, and contributes to ETEC pathogenesis in a neonatal mouse infection model. The objectives of this work were to evaluate LngA major subunit purified protein and CS21 purified pili on immunogenicity and protection against ETEC colonization of mice intestine. Recombinant LngA purified protein or purified CS21 pili from E9034A ETEC strain were evaluated for immunogenicity after immunization of C57BL/6 mice. Specific anti-LngA antibodies were detected from mice serum, feces, and intestine fluid samples by ELISA assays. Protection against gut colonization was evaluated on immunized mice orally challenged with wild type E9034A ETEC strain and by subsequent quantification of bacterial colony forming units (CFU) recovered from feces. Recombinant LngA protein and CS21 pili induced specific humoral and mucosal anti-LngA antibodies in the mouse model. CS21 combined with CT delivered intranasally as well as LngA combined with incomplete Freund adjuvant delivered intraperitoneally inhibited ETEC gut colonization in a mouse model. In conclusion, both LngA purified protein and CS21 pili from ETEC are highly immunogenic and may inhibit ETEC intestinal shedding. Our data on immunogenicity and immunoprotection indicates that CS21 is a suitable vaccine candidate for a future multivalent vaccine against ETEC diarrhea.


      PubDate: 2016-02-09T19:34:42Z
       
  • Antibodies derived from a toxoid MEFA (multiepitope fusion antigen) show
           neutralizing activities against heat-labile toxin (LT), heat-stable toxins
           (STa, STb), and Shiga toxin 2e (Stx2e) of porcine enterotoxigenic
           Escherichia coli (ETEC)
    • Abstract: Publication date: Available online 6 February 2016
      Source:Veterinary Microbiology
      Author(s): Dana Rausch, Xiaosai Ruan, Rahul Nandre, Qiangde Duan, Emad Hashish, Thomas A. Casey, Weiping Zhang
      Enterotoxigenic Escherichia coli (ETEC) strains are the main cause of diarrhea in pigs. Pig diarrhea especially post-weaning diarrhea remains one of the most important swine diseases. ETEC bacterial fimbriae including K88, F18, 987P, K99 and F41 promote bacterial attachment to intestinal epithelial cells and facilitate ETEC colonization in pig small intestine. ETEC enterotoxins including heat-labile toxin (LT) and heat-stable toxins type Ia (porcine-type STa) and type II (STb) stimulate fluid hyper-secretion, leading to watery diarrhea. Blocking bacteria colonization and/or neutralizing enterotoxicity of ETEC toxins are considered effective prevention against ETEC diarrhea. In this study, we applied the MEFA (multiepitope fusion antigen) strategy to create toxoid MEFAs that carried antigenic elements of ETEC toxins, and examined for broad antitoxin immunogenicity in a murine model. By embedding STa toxoid STaP12F (NTFYCCELCCNFACAGCY), a STb epitope (KKDLCEHY), and an epitope of Stx2e A subunit (QSYVSSLN) into the A1 peptide of a monomeric LT toxoid (LTR192G), two toxoid MEFAs, ‘LTR192G-STb-Stx2e-STaP12F’ and ‘LTR192G-STb-Stx2e-3xSTaP12F’ which carried three copies of STaP12F, were constructed. Mice intraperitoneally immunized with each toxoid MEFA developed IgG antibodies to all four toxins. Induced antibodies showed in vitro neutralizing activities against LT, STa, STb and Stx2e toxins. Moreover, suckling piglets born by a gilt immunized with ‘LTR192G-STb-Stx2e-3xSTaP12F’ were protected when challenged with ETEC strains, whereas piglets born by a control gilt developed diarrhea. Results from this study showed that the toxoid MEFA induced broadly antitoxin antibodies, and suggested potential application of the toxoid MEFA for developing a broad-spectrum vaccine against ETEC diarrhea in pigs.


      PubDate: 2016-02-09T19:34:42Z
       
  • Existence of two groups of Staphylococcus aureus strains isolated from
           bovine mastitis based on biofilm formation, intracellular survival,
           capsular profile and agr-typing
    • Abstract: Publication date: 15 March 2016
      Source:Veterinary Microbiology, Volume 185
      Author(s): Marjorie Bardiau, Jonathan Caplin, Johann Detilleux, Hans Graber, Paolo Moroni, Bernard Taminiau, Jacques G. Mainil
      Staphylococcus (S.) aureus is recognised worldwide as an important pathogen causing contagious acute and chronic bovine mastitis. Chronic mastitis account for a significant part of all bovine cases and represent an important economic problem for dairy producers. Several properties (biofilm formation, intracellular survival, capsular expression and group agr) are thought to be associated with this chronic status. In a previous study, we found the existence of two groups of strains based on the association of these features. The aim of the present work was to confirm on a large international and non-related collection of strains the existence of these clusters and to associate them with case history records. In addition, the genomes of eight strains were sequenced to study the genomic differences between strains of each cluster. The results confirmed the existence of both groups based on capsular typing, intracellular survival and agr-typing: strains cap8-positive, belonging to agr group II, showing a low invasion rate and strains cap5-positive, belonging to agr group I, showing a high invasion rate. None of the two clusters were associated with the chronic status of the cow. When comparing the genomes of strains belonging to both clusters, the genes specific to the group “cap5-agrI” would suggest that these strains are better adapted to live in hostile environment. The existence of these two groups is highly important as they may represent two clusters that are adapted differently to the host and/or the surrounding environment.


      PubDate: 2016-02-09T19:34:42Z
       
  • Comparative genomics of toxigenic and non-toxigenic Staphylococcus hyicus
    • Abstract: Publication date: Available online 25 January 2016
      Source:Veterinary Microbiology
      Author(s): Pimlapas Leekitcharoenphon, Sünje Johanna Pamp, Lars Ole Andresen, Frank M. Aarestrup
      The most common causative agent of exudative epidermitis (EE) in pigs is Staphylococcus hyicus. S. hyicus can be grouped into toxigenic and non-toxigenic strains based on their ability to cause EE in pigs and specific virulence genes have been identified. A genome wide comparison between non-toxigenic and toxigenic strains has never been performed. In this study, we sequenced eleven toxigenic and six non-toxigenic S. hyicus strains and performed comparative genomic and phylogenetic analysis. Our analyses revealed two genomic regions encoding genes that were predominantly found in toxigenic strains and are predicted to encode for virulence determinants for EE. All toxigenic strains encoded for one of the exfoliative toxins ExhA, ExhB, ExhC, or ExhD. In addition, one of these regions encoded for an ADP-ribosyltransferase (EDIN, epidermal cell differentiation inhibitor) and a novel putative RNase toxin (polymorphic toxin) and was associated with the gene encoding ExhA. A clear differentiation between toxigenic and non-toxigenic strains based on genomic and phylogenetic analysis was not apparent. The results of this study support the observation that exfoliative toxins of S. hyicus and S. aureus are located on genetic elements such as pathogenicity islands, phages, prophages and plasmids.


      PubDate: 2016-01-29T17:35:25Z
       
  • African swine fever virus: current state and future perspectives in
           vaccine and antiviral research
    • Abstract: Publication date: Available online 25 January 2016
      Source:Veterinary Microbiology
      Author(s): Hovakim Zakaryan, Yolanda Revilla
      African swine fever (ASF) is among the most significant of swine diseases for which no effective vaccines and antivirals are available. The disease, which is endemic in Africa, was introduced to Trans-Caucasian countries and the Russian Federation in 2007, where it remains prevalent today among domestic pigs and wild boars. Although some measures were implemented, ASF continues to pose a global risk for all countries, and thereby highlighting the importance of vaccine and antiviral research. In this review, an overview of research efforts toward the development of effective vaccines during the past decades is presented. As an alternative to vaccine development, the current state in antiviral research against ASFV is also presented. Finally, future perspectives in vaccine and antiviral research giving emphasis on some strategies that may allow researchers to develop effective countermeasures against ASF are discussed.


      PubDate: 2016-01-29T17:35:25Z
       
  • The Functions of the Variable Lipoprotein Family of Mycoplasma hyorhinis
           in Adherence to Host Cells
    • Abstract: Publication date: Available online 27 January 2016
      Source:Veterinary Microbiology
      Author(s): Qiyan Xiong, Jia Wang, Yan Ji, Bo Ni, Bixiong Zhang, Qinghong Ma, Yanna Wei, Shaobo Xiao, Zhixin Feng, Maojun Liu, Guoqing Shao
      Mycoplasma hyorhinis (M. hyorhinis) is a swine pathogen that is associated with various human cancers and contamination in cell cultures. However, no studies on the adhesion molecules of this pathogen have yet been reported. The variable lipoprotein (Vlp) family is an important surface component of M. hyorhinis. Herein, we performed several experiments to identify the function of the Vlp family in adherence to host cells. Seven recombinant Vlp (rVlp) proteins were expressed in Escherichia coli and purified by affinity chromatography. The potential role of rVlp adherence to pig kidney (PK-15) and swine tracheal epithelial (STEC) cells was then studied by indirect immunofluorescence assay and microtiter plate adherence assay. Adhesion of M. hyorhinis to PK-15 and STEC cells was specifically inhibited by the addition of a cocktail of rVlp proteins. The rVlp protein mixture was shown to bind to both PK-15 and STEC cells. The binding increased in a dose-dependent manner and could be blocked by antisera against the rVlp proteins. Most of the rVlp proteins could bind individually to both PK-15 and STEC cells except for rVlpD and rVlpF, which bound only to STEC cells. Because Vlp members vary in size among different strains and generations, they may vary in their cytoadhesion capabilities in various strains. In summary, the present results indicate that the Vlp family functions as adhesins of M. hyorhinis.


      PubDate: 2016-01-29T17:35:25Z
       
  • Lack of association between polymorphic copies of endogenous Jaagsiekte
           Sheep Retrovirus (enJSRVs) and Ovine Pulmonary Adenocarcinoma
    • Abstract: Publication date: Available online 28 January 2016
      Source:Veterinary Microbiology
      Author(s): Maialen Sistiaga-Poveda, Amaia Larruskain, Maider Mateo-Abad, Begoña M. Jugo
      Ovine Pulmonary Adenocarcinoma (OPA) is a retrovirus-induced lung tumor of sheep, goat and mouflon, and its etiologic agent, Jaagsiekte sheep retrovirus (JSRV) is the only virus known to cause a naturally occurred lung adenocarcinoma. The oncogenic JSRV has several endogenous counterparts termed enJSRVs, some of which have been shown to interfere with JSRV replication at early and late stages of the retroviral cycle inhibiting JSRV exit from the cell, and thus, protecting sheep against the infection. In this work, Latxa sheep breed animals were classified depending on the presence/absence of OPA-characteristic clinical lesions in the lung. Using a PCR genotyping method and a logistic regression-based association study, five polymorphic enJSRV copies were analyzed in 49 OPA positive sheep and 124 control individuals. Our results showed that the frequency of the provirus enJSRV-16 is much higher in Latxa sheep breed than in other breeds, suggesting a recent proliferation of this provirus in the studied breed. However, no polymorphic enJSRV was found to be statistically associated with the susceptibility/resistance to OPA development.


      PubDate: 2016-01-29T17:35:25Z
       
  • Characterization and pathogenic role of outer membrane vesicles produced
           by the fish pathogen Piscirickettsia salmonis under in vitro conditions
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): Cristian Oliver, Karla Valenzuela, Mauricio Hernández, Rodrigo Sandoval, Ronie E. Haro, Ruben Avendaño-Herrera, Juan G. Cárcamo, Maite T. Villar, Antonio Artigues, Rafael Garduño, Alejandro J. Yáñez
      Piscirickettsia salmonis is one of the major fish pathogens affecting Chilean aquaculture. This Gram-negative bacterium is highly infectious and is the etiological agent of Piscirickettsiosis. Little is currently known about how the virulence factors expressed by P. salmonis are delivered to host cells. However, it is known that several Gram-negative microorganisms constitutively release outer membrane vesicles (OMVs), which have been implicated in the delivery of virulence factors to host cells. In this study, OMVs production by P. salmonis was observed during infection in CHSE-214 cells and during normal growth in liquid media. The OMVs were spherical vesicles ranging in size between 25 and 145nm. SDS-PAGE analysis demonstrated that the protein profile of the OMVs was similar to the outer membrane protein profile of P. salmonis. Importantly, the bacterial chaperonin Hsp60 was found in the OMVs of P. salmonis by Western-blot and LC–MS/MS analyses. Finally, in vitro infection assays showed that purified OMVs generated a cytopathic effect on CHSE-214 cells, suggesting a role in pathogenesis. Therefore, OMVs might be an important vehicle for delivering effector molecules to host cells during P. salmonis infection.


      PubDate: 2016-01-29T17:35:25Z
       
  • The viral non-structural protein 1 alpha (Nsp1α) inhibits p53
           apoptosis activity by increasing murine double minute 2 (mdm2) expression
           in porcine reproductive and respiratory syndrome virus (PRRSV)
           early-infected cells
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): Xiaodu Wang, Chunyan Shao, Luyan Wang, Qunjing Li, Houhui Song, Weihuan Fang
      Apoptosis is one of the most important mechanisms of pathogenesis in porcine reproductive and respiratory syndrome virus (PRRSV)-infected cells. The tumor suppressor p53 plays a critical role in apoptotic induction in viral infections. In the present study, we found that p53 activity was inhibited at the early stage of PRRSV infection in both the highly pathogenic (HP) and lowly pathogenic (LP) PRRSV isolates. Bax expression showed a similar change pattern to that of p53. Murine double minute 2 (mdm2) expressed higher in PRRSV-infected cells than in uninfected cells at the early stage of infection and promoted p53 degradation. We show for the first time that the non-structural protein 1 alpha (Nsp1α) of PRRSV is a negative regulator of p53 activity through increasing mdm2 expression and p53 ubiquitination, while p53 is inhibitory to PRRSV replication at the early stage of infection. We conclude that PRRSV manipulates the host factors mdm2 and p53 via its Nsp1α for increased replication at the early stage of infection. These provide a novel perspective to understand the interaction between apoptosis and replication of PRRSV.


      PubDate: 2016-01-24T14:12:32Z
       
  • Innate and adaptive immune responses to tick-borne flavivirus infection in
           sheep
    • Abstract: Publication date: Available online 22 January 2016
      Source:Veterinary Microbiology
      Author(s): Karen L. Mansfield, Nicholas Johnson, Ashley C. Banyard, Alejandro Núñez, Matthew Baylis, Tom Solomon, Anthony R. Fooks
      The flaviviruses tick-borne encephalitis virus (TBEV) and louping ill virus (LIV) are closely-related genetically and antigenically, have broadly similar host ranges that include rodents and other mammals (including sheep), and are both transmitted by the same tick species, Ixodes ricinus. Although human infection with TBEV results in a febrile illness followed in some cases by encephalitis, humans appear to be much less susceptible to infection with LIV. However, these viruses demonstrate different susceptibilities in sheep; LIV infection causes encephalitic disease, whereas TBEV infection generally does not. To investigate the role of the immune response in this mixed outcome, groups of sheep were inoculated with either virus, or with a primary inoculation with one virus and secondary inoculation with the other. Markers of both adaptive and innate immune responses were measured. In each group studied, infection resulted in seroconversion, demonstrated by the detection of virus specific neutralising antibodies. This appeared to control infection with TBEV but not LIV, which progressed to a febrile infection, with transient viraemia and elevated levels of serum interferon. This was followed by neuroinvasion, leading to up-regulation of innate immune transcripts in discrete areas of the brain, including interferon inducible genes and chemokines. Prior inoculation with TBEV did not prevent infection with LIV, but did appear to reduce disease severity and viraemia. We postulate that LIV has adapted to replicate efficiently in sheep cells, and disseminate rapidly following infection. By contrast, TBEV fails to disseminate in sheep and is controlled by the immune response.


      PubDate: 2016-01-24T14:12:32Z
       
  • Antiviral activities of 2,6-diaminopurinebased acyclic nucleoside
           phosphonates against herpesviruses: In vitro study results with
           pseudorabies virus (PrV, SuHV-1)
    • Abstract: Publication date: Available online 18 January 2016
      Source:Veterinary Microbiology
      Author(s): Darina Zouharova, Ivana Lipenska, Martina Fojtikova, Pavel Kulich, Jiri Neca, Michal Slany, Kamil Kovarcik, Pavlina Turanek-Knotigova, Frantisek Hubatka, Hana Celechovska, Josef Masek, Stepan Koudelka, Lubomir Prochazka, Ludek Eyer, Jana Plockova, Eliska Bartheldyova, Andrew D. Miller, Daniel Ruze, Milan Raska, Zlatko Janeba, Jaroslav Turanek
      Pseudorabies virus (PrV), a causative agent of Aujeszkýs disease, is deadly to most mammals with the exception of higher primates and men. This disease causes serious economic loses among farm animals, especially pigs, yet many European countries are today claimed to be Aujeszkýs disease free because of the discovery of an efficient vaccination for pigs. In reality, the virus is still present in wild boar. Current vaccines are neither suitable for dogs nor are there anti-PrV drugs approved for veterinary use. Therefore, the disease still represents a high threat, particularly for expensive hunting dogs that can come into close contact with infected boars. Here we report on the anti-PrV activities of a series of synthetic diaminopurine-based acyclic nucleoside phosphonate (DAP-ANP) analogues. Initially, all synthetic DAP-ANPs under investigation are shown to exhibit minimal cytotoxicity by MTT and XTT tests (1–100μM range). Thereafter in vitro infection models are established using PrV virus SuHV-1, optimized on PK-15 and RK-13 cell lines. Out of the six DAP-ANP analogues tested, analogue VI functionalized with a cyclopropyl group on the 6-amino position of the purine ring proves the most effective antiviral DAP-ANP analogue against PrV infection, aided by sufficient hydrophobic character to enhance bioavailability to its cellular target viral DNA-polymerase. Four other DAP-ANP analogues with functional groups introduced to the C2’position are shown ineffective against PrV infection, even with favourable hydrophobic properties. Cidofovir®, a drug approved against various herpesvirus infections, is found to exert only low activity against PrV in these same in vitro models.


      PubDate: 2016-01-20T14:06:55Z
       
  • Co-colonization and clonal diversity of Methicillin-sensitive and
           Methicillin-resistant Staphylococcus aureus in sows
    • Abstract: Publication date: Available online 18 January 2016
      Source:Veterinary Microbiology
      Author(s): Alexandra Fetsch, Uwe Roesler, Britta Kraushaar, Anika Friese
      Methicillin-susceptible Staphylococcus (S.) aureus (MSSA) and methicillin-resistant S. aureus (MRSA) are colonizers of skin and mucosa. In humans, MSSA and MRSA compete for colonization space in the anterior nares of pig farmers; however, it was also shown that MSSA/MRSA co-colonization is common and one clone can be found rather than differing types of MSSA and MRSA. We investigated the colonization and clonality of both, MSSA and MRSA in pigs over a longer time. Eighteen sows were nasally sampled three times every ten weeks. Additionally, environmental samples were taken. Samples were investigated for MSSA and MRSA, respectively. The spa type was defined from up to five MRSA and MSSA isolates found per sample and sampling time; selected isolates were further investigated by microarray. Three sows (16.7%) were completely negative for MSSA and MRSA. Twelve pigs (66.7%) were irregularly positive for both, MSSA and MRSA over the time, whereas seven out of them (38.9%) were simultaneously colonized. CC398 (t034, t011) MRSA and CC9 (t337, t1430, and t13816) MSSA associated spa types were exclusively found. In 44.4% (n=8) of sows up to two different types of MSSA were present at the same time and sample. Strains of the same clonal lineage showed a high genetic identity despite their origin. Highly identic clones were present in sows and their environment. As conclusion, MSSA/MRSA may not exclude each other in the anterior nares of pigs. Pigs may also carry different clones at the same time.


      PubDate: 2016-01-20T14:06:55Z
       
  • A model to investigate the optimal seeder-to-naïve ratio for
           successful natural Mycoplasma hyopneumoniae gilt exposure prior to
           entering the breeding herd
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): Luiza R. Roos, Eduardo Fano, Nitipong Homwong, Brian Payne, Maria Pieters
      Due to the significance of Mycoplasma hyopneumoniae as a swine respiratory pathogen, acclimation measures are taken into consideration when obtaining replacement gilts from negative sources to be introduced to endemically infected herds. The aim of this study was to evaluate the optimum seeder-to-naïve gilt ratio in a 4-week period for successful natural exposure to M. hyopneumoniae. Sixty gilts were divided in two groups, 21 2-week old seeder gilts were inoculated with M. hyopneumoniae, and 39 aged-matched naïve gilts were exposed to the seeders during a 4-week period. The exposure was set by dividing the gilts into six groups of 10 with different ratios of seeder-to-naïve, from 1:9 until 6 seeders and 4 naïve gilts. Laryngeal swabs, oral fluids and blood samples were collected from all gilts prior to, during and after inoculation and exposure. Infection in seeders was confirmed by development of clinical signs, seroconversion post-inoculation, and detection of M. hyopneumoniae genetic material. Naïve were considered positive after 4 weeks if M. hyopneumoniae was detected on bronchial swab or fixed lung tissue. As result, 33% (3/9) naïve gilts were positive in the 1:9 ratio, 75% (6/8) in 2:8, 28% (2/7) in 3:7, 33% (2/6) in 4:6, 80% (4/5) in 5:5 and 100% (4/4) in the 6:4 ratio. The estimated transmission rate (β) and expected probability of infection (ψ) were 1.28 per pig/week and 0.6, respectively. In this study, six seeders were required in a group of 10 gilts for successful exposure to M. hyopneumoniae in a 4-week exposure period.


      PubDate: 2016-01-20T14:06:55Z
       
  • Transferable genes putatively conferring elevated minimum inhibitory
           concentrations of narasin in Enterococcus faecium from Swedish broilers
    • Abstract: Publication date: Available online 18 January 2016
      Source:Veterinary Microbiology
      Author(s): Oskar Nilsson, Mattias Myrenås, Joakim Ågren
      The minimum inhibitory concentration (MIC) of the polyether ionophore antibiotic narasin is elevated in a large proportion of Enterococcus faecium from Swedish broilers. The aim of this study was to identify gene(s) responsible for these elevated MICs. Six plasmids, four conferring vancomycin resistance and elevated MIC of narasin and two only conferring resistance to vancomycin, were sequenced. The genes for a putative mechanism for elevated MIC of narasin was used to design a PCR assay which in turn was used to screen 100 isolates of E. faecium from Swedish broilers. A 5.9kb area was only found in the plasmids transferring elevated MIC of narasin. This area included two genes coding for an ABC-type transporter; an ‘ABC transporter permease protein’ and an ‘ABC-type multidrug transport system, ATPase component’. These genes are known to confer resistance to the ionophore tetronasin. PCR investigation confirmed a correlation between the presence of the genes and a MIC of narasin ≥2mg/L. The results of this study indicate that the ABC permease together with the ABC ATPase are responsible for the elevated MIC of narasin present among E. faecium in Swedish broilers. To our knowledge, this is the first description of a putative transferable mechanism for elevated MIC of narasin.


      PubDate: 2016-01-20T14:06:55Z
       
  • Acute phase protein and antioxidant responses in dogs with experimental
           acute monocytic ehrlichiosis treated with rifampicin
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): Dimitra Karnezi, Jose J. Ceron, Konstantina Theodorou, Leonidas Leontides, Victoria I. Siarkou, Silvia Martinez, Asta Tvarijonaviciute, Shimon Harrus, Christos K. Koutinas, Dimitra Pardali, Mathios E. Mylonakis
      There is currently lack of information on the changes of acute phase proteins (APP) and antioxidant markers and their clinical relevance as treatment response indicators in canine monocytic ehrlichiosis (CME). The objective of this study was to investigate the patterns of C-reactive protein (CRP), haptoglobin (Hp), ferritin and paraoxonase-1 (PON-1) during treatment of dogs with acute CME with rifampicin. Blood serum samples from ten Beagle dogs with experimental acute CME were retrospectively examined. Five dogs (Group A) were treated with rifampicin (10mg/Kg/24h), per os, for 3 weeks and 5 dogs (Group B) received no treatment (infected controls). Two Beagle dogs served as uninfected controls. Blood serum samples were serially examined prior to Ehrlichia canis inoculation and on post-inoculation days 14, 21, 28, 35 and 42. Significant changes of CRP, Hp, ferritin and PON-1 values were found in the majority of infected dogs. However, their concentrations did not differ between the two groups during the treatment observation period. The results of this study indicate that although several APP and PON-1 tend to significantly change in the majority of dogs with acute CME, they were of limited clinical relevance as treatment response indicators in this experimental setting.


      PubDate: 2016-01-20T14:06:55Z
       
  • Streptococcus agalactiae in the environment of bovine dairy herds –
           rewriting the textbooks'
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): H.J. Jørgensen, A.B. Nordstoga, S. Sviland, R.N. Zadoks, L. Sølverød, B. Kvitle, T. Mørk
      Many free-stall bovine dairy herds in Norway fail to eradicate Streptococcus agalactiae despite long-term control measures. In a longitudinal study of 4 free-stall herds with automatic milking systems (AMS), milk and extramammary sites were sampled 4 times with 1-2 month intervals. Composite milk, rectal- and vaginal swabs were collected from dairy cows; rectal swabs from heifers and young stock; rectal- and tonsillar swabs from calves; and environmental swabs from the AMS, the floors, cow beds, watering and feeding equipment. A cross sectional study of 37 herds was also conducted, with 1 visit for environmental sampling. Fifteen of the herds were known to be infected with S. agalactiae while the remaining 22 had not had evidence of S. agalactiae mastitis in the preceding 2 years. All samples were cultured for S. agalactiae, and selected isolates (n =54) from positive herds were genotyped by Multi Locus Sequence Typing (MLST). Results show that the bovine gastrointestinal tract and the dairy cow environment are reservoirs of S. agalactiae, and point to the existence of 2 transmission cycles; a contagious transmission cycle via the milking machine and an oro-fecal transmission cycle, with drinking water as the most likely vehicle for transmission. Ten sequence types were identified, and results suggest that strains differ in their ability to survive in the environment and transmit within dairy herds. Measures to eradicate S. agalactiae from bovine dairy herds should take into account the extra-mammary reservoirs and the potential for environmental transmission of this supposedly exclusively contagious pathogen.


      PubDate: 2016-01-20T14:06:55Z
       
  • Characterization of monoclonal antibodies against feline coronavirus
           accessory protein 7b
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): Tanja Lemmermeyer, Benjamin Lamp, Rainer Schneider, John Ziebuhr, Gergely Tekes, Heinz-Jürgen Thiel
      Feline coronaviruses (FCoVs) encode five accessory proteins termed 3a, 3b, 3c, 7a and 7b of unknown function. These proteins are dispensable for viral replication in vitro but are supposed to play a role in virulence. In the current study, we produced and characterized 7b-specific monoclonal antibodies (mAbs). A recombinant form of the 7b protein was expressed as a fusion protein in Escherichia coli, purified by immobilized metal affinity chromatography and used as immunogen. Two hybridoma lines, 5B6 and 14D8, were isolated that expressed mAbs that recognized 7b proteins of both FCoV serotypes. Using an extensive set of N- and C-terminally truncated 7b proteins expressed in E. coli and a synthetic peptide, the binding sites of mAbs 5B6 and 14D8 were mapped to an 18-residue region that comprises the only potential N-glycosylation site of the FCoV 7b protein. The two mAbs were suitable to detect a 24-kDa protein, which represents the nonglycosylated form of 7b in FCoV-infected cells. We speculate that glycosylation of 7b is part of the viral evasion strategy to prevent an immune response against this antigenic site.


      PubDate: 2016-01-16T11:00:53Z
       
  • Characterization of specific antigenic epitopes and the nuclear export
           signal of the Porcine circovirus 2 ORF3 protein
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): Jinyan Gu, Lun Wang, Yulan Jin, Cui Lin, Huijuan Wang, Niu Zhou, Gang Xing, Min Liao, Jiyong Zhou
      Porcine circovirus 2 (PCV2) is the etiological agent of postweaning multisystemic wasting syndrome. PCV2 ORF3 protein is a nonstructural protein known to induce apoptosis, but little is known about the biological function of ORF3 protein. Therefore, we undertook this study to map ORF3 protein epitopes recognized by a panel of monoclonal antibodies (mAbs) and to characterize putative nuclear localization (NLS) and nuclear export (NES) sequences in ORF3. The linear epitopes targeted by two previously published mAbs 3B1 and 1H3 and a novel mouse mAb 3C3 were defined using overlapping pools of peptides. Here, we find that ORF3 in PCV2 infected cells contains a conformational epitope targeted by the antibody 3C3, which is distinct from linear epitopes recognized by the antibodies 3B1 and 1H3 in recombinant ORF3 protein. These results suggest that the linear epitope recognized by 3B1 and 1H3 is masked in PCV2 infected cells, and that the conformational epitope is unique to PCV2 infection. Furthermore, we find that ORF3 protein expressed in cytoplasm in early stages of PCV2 infection and then accumulated in nucleus over time. Moreover, we localize a NES at the N-terminus (residues 1–35aa) of ORF3 which plays critical role in nuclear export activity. These findings provide a novel insight that deepens our understanding of the biological function of PCV2 ORF3.


      PubDate: 2016-01-16T11:00:53Z
       
  • Shiga toxin-producing Escherichia coli (STEC): Zoonotic risks associated
           with psittacine pet birds in home environments
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): R.M. Gioia-Di Chiacchio, M.P.V. Cunha, R.M. Sturn, L.Z. Moreno, A.M. Moreno, C.B.P. Pereira, F.H. Martins, M.R. Franzolin, R.M.F. Piazza, T. Knöbl
      Psittacidae are frequentely bred as pets worldwide, but little is known about the zoonotic risks of these animals. The objective of this study was to investigate the presence of Shiga toxin-producing Escherichia coli (STEC) in the feces of psittacine birds housed as pets. A total of 171 fecal samples (67 cockatiels, 59 budgerigars, and 45 agapornis) were cultured. Forty-two (E. coli) strains were identified, and the presence of the eae, stx1, and stx2 genes was determined using PCR. The antimicrobial resistance profiles of the STEC strains were determined using the disk diffusion method and phylogenetic analysis according to the new Clermont phylotyping method. Using these methods, 19.4% (8/42) of the STEC strains were determined to be positive for the eae and stx2 genes. The results revealed a STEC frequency of 4.6% in the birds (8/171), with a percentage of 8.47% in budgerigars (5/59), 4.47% in cockatiels (3/67), and 0% in agapornis (0/45). None of the STEC isolates belonged to the O157 serogroup. Most of the strains were classified as sensitive to the 18 antibiotics tested. None of the strains exhibited a multiresistance profile. In the phylogenetic analysis, two strains were classified as non-typeable, three were classified as B2, two were classified as F, and one was classified as Clade I. Seven of the eight STEC strains showed a clonal profile using AFLP. E. coli strains that are stx2+ plus eae+ are usually associated with severe human diseases such as hemorrhagic colitis and hemolytic-uremic syndrome. The STEC-positive results indicate the zoonotic risk of breeding psittacidae in home environments.


      PubDate: 2016-01-16T11:00:53Z
       
  • Linear antigenic mapping of flagellin (FliC) from Salmonella enterica
           serovar Enteritidis with yeast surface expression system
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): Gaoling Wang, Bingtian Shi, Tao Li, Teng Zuo, Bin Wang, Wei Si, Jiuqing Xin, Kongbin Yang, Xuanlin Shi, Siguo Liu, Henggui Liu
      Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major cause of food-borne illness around the world and can have significant health implications in humans, poultry and other animals. Flagellin (FliC) is the primary component of bacterial flagella. It has been shown that the FliC of S. Enteritidis is a significant antigenic structure and can elicit strong humoral responses against S. Enteritidis infection in chickens. Here, we constructed a FliC antigen library using a yeast surface expression system. Yeast cells expressing FliC peptide antigens were labeled with chicken sera against S. Enteritidis and sorted using FACS. The analyses of FliC peptides revealed that the FliC linear antigenicity in chickens resided on three domains which were able to elicit strong humoral responses in vivo. Animal experiments further revealed that the antibodies elicited by these antigenic domains were able to significantly inhibit the invasion of S. Enteritidis into the liver and spleen of chickens. These findings will facilitate our better understanding of the humoral responses elicited by FliC in chickens upon infection by S. Enteritidis.


      PubDate: 2016-01-16T11:00:53Z
       
  • Co-infection of classic swine H1N1 influenza virus in pigs persistently
           infected with porcine rubulavirus
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): José Francisco Rivera-Benitez, Jazmín De la Luz-Armendáriz, Manuel Saavedra-Montañez, Miguel Ángel Jasso-Escutia, Ivan Sánchez-Betancourt, Armando Pérez-Torres, Julio Reyes-Leyva, Jesús Hernández, Atalo Martínez-Lara, Humberto Ramírez-Mendoza
      Porcine rubulavirus (PorPV) and swine influenza virus infection causes respiratory disease in pigs. PorPV persistent infection could facilitate the establishment of secondary infections. The aim of this study was to analyse the pathogenicity of classic swine H1N1 influenza virus (swH1N1) in growing pigs persistently infected with porcine rubulavirus. Conventional six-week-old pigs were intranasally inoculated with PorPV, swH1N1, or PorPV/swH1N1. A mock-infected group was included. The co-infection with swH1N1 was at 44 days post-infection (DPI), right after clinical signs of PorPV infection had stopped. The pigs of the co-infection group presented an increase of clinical signs compared to the simple infection groups. In all infected groups, the most recurrent lung lesion was hyperplasia of the bronchiolar-associated lymphoid tissue and interstitial pneumonia. By means of immunohistochemical evaluation it was possible to demonstrate the presence of the two viral agents infecting simultaneously the bronchiolar epithelium. Viral excretion of PorPV in nasal and oral fluid was recorded at 28 and 52 DPI, respectively. PorPV persisted in several samples from respiratory tissues (RT), secondary lymphoid organs (SLO), and bronchoalveolar lavage fluid (BALF). For swH1N1, the viral excretion in nasal fluids was significantly higher in single-infected swH1N1 pigs than in the co-infected group. However, the co-infection group exhibited an increase in the presence of swH1N1 in RT, SLO, and BALF at two days after co-infection. In conclusion, the results obtained confirm an increase in the clinical signs of infection, and PorPV was observed to impact the spread of swH1N1 in analysed tissues in the early stage of co-infection, although viral shedding was not enhanced. In the present study, the interaction of swH1N1 infection is demonstrated in pigs persistently infected with PorPV.


      PubDate: 2016-01-16T11:00:53Z
       
  • Molecular and antibiotic susceptibility characterization of Aerococcus
           viridans isolated from porcine urinary infection
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): Luisa Z. Moreno, Carlos E.C. Matajira, Vasco T.M. Gomes, Ana Paula S. Silva, Renan E. Mesquita, Ana Paula G. Christ, Maria Inês Z. Sato, Andrea M. Moreno
      Aerococcus viridans has been reported as a human and animal pathogen causing urinary tract infection, arthritis, pneumonia, meningitis and endocarditis. Routinely, A. viridans is not surveyed in clinical diagnosis laboratories and commonly is misidentified as other bacteria. There is no concrete data on the prevalence and impact of the pathogen to both human and animal health. In the present study, we report the isolation and molecular and antibiotic susceptibility characterization of A. viridans strains from porcine urinary infections. A total of 22 isolates were identified as A. viridans by MALDI-TOF MS and confirmed by 16S rRNA gene sequencing. Isolates were genotyped by single enzyme amplified fragments length polymorphism (SE-AFLP) that resulted in 19 clusters of which 81.2% were composed by single isolates. The high genetic heterogeneity corroborates previous studies and appears to be a particularity of A. viridans. The minimal inhibitory concentration (MIC) values also presented variability especially for ceftiofur, fluoroquinolones and aminoglycosides. The high MICs of aminoglycosides, tetracyclines and macrolides seen among the A. viridans corroborate previous reports and the widespread veterinary usage of these antibiotics demand attention for the implication of A. viridans infection to both human and animal health.


      PubDate: 2016-01-12T10:38:29Z
       
  • IFC - Aims & Scope, EDB, Publication Information
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183




      PubDate: 2016-01-12T10:38:29Z
       
  • The first reported Florida clade 1 virus in the Nordic countries, isolated
           from a Swedish outbreak of equine influenza in 2011
    • Abstract: Publication date: 29 February 2016
      Source:Veterinary Microbiology, Volume 184
      Author(s): Helena Back, Louise Treiberg Berndtsson, Gittan Gröndahl, Karl Ståhl, John Pringle, Siamak Zohari
      Equine Influenza Virus (EIV) is a major cause of respiratory disease in horses and the virus constantly undergoes antigenic drift. Here we characterize and describe the HA1 and the NA genes of H3N8 within samples obtained from outbreaks in Sweden during November–December 2011. Both clade 1 and clade 2 viruses of the Florida sublineage were identified. The index case of clade 2 was transported to Sweden from Spain through the Netherlands, whereas the clade 1 had its origin from a Swedish stud farm. The clade 1 virus was efficiently spread between training yards by unvaccinated young horses, but vaccinated horses were also presented with clinical signs of respiratory disease. No virus of the Eurasian lineage was isolated during this outbreak. Clade 1 has previously been described in outbreaks in numerous of other countries, but this is the first time it has been detected in Sweden. The results from this study shows the importance of including both clade 1 and clade 2 of the Florida sublineage in equine influenza vaccines, supporting the ESP and OIE recommendations.


      PubDate: 2016-01-08T12:55:22Z
       
  • Longitudinal study on the colonisation and transmission of
           methicillin-resistant Staphylococcus aureus in pig farms
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Patrick Daniel Bangerter, Xaver Sidler, Vincent Perreten, Gudrun Overesch
      Knowledge about the dynamics of methicillin-resistant Staphylococcus aureus (MRSA) in pigs lacks detail at the level of individual animal. The aim of our study was therefore to determine the colonisation status of MRSA in individual pigs from birth to slaughter in order to gain a better understanding of substantial factors involved in transmission. Two farrow-to-finish and two grow-to-finish herds were included in the study. A total of 1728 nasal swabs from 390 pigs and 592 environmental wipes were collected at 11 different time points. Intermittent colonisation throughout the entire production cycle was conspicuous in the tracking of MRSA in individual pigs. Almost all pigs from a MRSA-positive herd changed MRSA status several times, which implies that pigs are transiently rather than permanently colonised. We highly recommend the definition of MRSA status at herd level rather that at the level of the individual pig when considering prevention measures against MRSA. Therefore, to avoid the further spread of MRSA in countries with moderate prevalence, such as in Switzerland, defining farms as MRSA positive or MRSA negative and allowing the trade of pigs only within herds of the same status seems feasible. This will also be important for combating the further dissemination of livestock-associated (LA)-MRSA into healthcare facilities and the community via humans who have close contact with animals.


      PubDate: 2016-01-03T03:27:33Z
       
  • Chronic West Nile virus infection in kea (Nestor notabilis)
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Tamás Bakonyi, Gyula K. Gajdon, Raoul Schwing, Wolfgang Vogl, Annett-Carolin Häbich, Denise Thaller, Herbert Weissenböck, Ivo Rudolf, Zdenek Hubálek, Norbert Nowotny
      Six kea (Nestor notabilis) in human care, naturally infected with West Nile virus (WNV) lineage 2 in Vienna, Austria, in 2008, developed mild to fatal neurological signs. WNV RNA persisted and the virus evolved in the birds’ brains, as demonstrated by (phylo)genetic analyses of the complete viral genomes detected in kea euthanized between 2009 and 2014. WNV antibodies persisted in the birds, too. Chronic WNV infection in the brain might contribute to the circulation of the virus through oral transmission to predatory birds.
      Graphical abstract image

      PubDate: 2016-01-03T03:27:33Z
       
  • Different counteracting host immune responses to clade 2.2.1.1 and 2.2.1.2
           Egyptian H5N1 highly pathogenic avian influenza viruses in naïve and
           vaccinated chickens
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Ahmed A. Samy, Mona I. El-Enbaawy, Ahmed A. El-Sanousi, Soad A. Nasef, Mahmoud M. Naguib, E.M. Abdelwhab, Hirokazu Hikono, Takehiko Saito
      In Egypt, two distinct lineages of H5N1 highly pathogenic avian influenza (HPAI) viruses, “classic 2.2.1.2” and “variant 2.2.1.1” strains, have evolved. The underlying host immune responses counteracting these viruses in chickens remain not well understood. In the present study, the cytokine responses to a classic strain (C121) and those to a variant strain (V1063) were compared in naïve and vaccinated chickens. In naïve chickens, the C121 replicated more efficiently than the V1063. Both the C121 and the V1063 increased interferon (IFN)-γ and interleukin (IL)-10 gene expression at 48h post inoculation (hpi) in the lung and spleen but the levels of these cytokines were lower in chickens infected with the C121 than those infected with the V1063. In contrast, in chickens vaccinated with inactivated C121-based vaccine, the C121 replicated less than the V1063. Both challenge with the C121 and that with the V1063 did not increase IFN-γ gene expression at 48 hpi; rather, the C121 increased IL-4 gene expression in the lung accompanied with lower viral titer and higher HI titers. These results suggested that the pathogenicity of HPAI viruses correlated with IFN-γ-producing helper and/or cytotoxic T cell responses in naïve chickens, whereas vaccine efficacy to HPAI viruses correlated with IL-4 producing helper T cell responses in the lung in vaccinated chickens. It implies that IL-4 in the lung, in addition to the traditional serum HI titers, could be used to screen novel vaccine strategies, such as strains, adjuvant, prime/boost protocols, against HPAI in chickens.


      PubDate: 2015-12-30T06:05:00Z
       
  • The neuropathogenic T953 strain of equine herpesvirus-1 inhibits type-I
           IFN mediated antiviral activity in equine endothelial cells
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Sanjay Sarkar, Udeni B.R. Balasuriya, David W. Horohov, Thomas M. Chambers
      Equine herpesvirus-1 (EHV-1) infects equine endothelial cells (EECs) lining the small blood vessels in the central nervous system. However, the effect of type I IFN on EHV-1 replication in the EECs is not well studied. Thus, the primary objective of this study was to investigate the effect of type-I IFN on the replication of the neuropathogenic T953 strain of EHV-1 in vitro in EECs. The initial data showed that the EHV-1 was partly resistant to the biological effect of exogenously supplied recombinant equine IFN-α. Subsequent investigation into the mechanism of resistance showed that EHV-1 infection of EECs interfered with the STAT-1 phosphorylation through which type-I IFN exerts its antiviral effect. Immunofluorescence staining showed interference with the translocation of STAT-1 molecules from cytoplasm to nucleus confirming the virus mediated suppression of STAT-1 activation. Downstream of the JAK-STAT signaling, EHV-1 infection inhibited expression of cellular antiviral proteins including IFN-stimulated gene 56 (ISG56) and viperin. Taken together these findings suggest that the neuropathogenic T953 strain of EHV-1 evades the host innate immune response by inhibiting IFN and this may provide some insight into the pathogenesis of EHV-1 infection.


      PubDate: 2015-12-30T06:05:00Z
       
  • Control of swine pseudorabies in China: Opportunities and limitations
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Yuan Sun, Yuzi Luo, Chun-Hua Wang, Jin Yuan, Na Li, Kun Song, Hua-Ji Qiu
      Pseudorabies (PR), also known as Aujeszky’s disease (AD), is caused by pseudorabies virus (PRV) or called suid herpesvirus 1 (SuHV-1). It is an economically significant viral disease of pigs and other animals. Although the disease has been eradicated in commercial swine populations of some countries using gE-deleted vaccines and differentiating infected from vaccinated animals (DIVA) strategy, PR continues to be one of the most important diseases of pigs in many countries, particularly in regions with dense pig populations, including China. This article reviews the current situation of PR in China, including epidemiology, diagnostic assays, control strategies and challenges of the disease. PR has been endemic in most provinces of China largely due to the lack of appropriate compulsory vaccination campaigns of pigs, sufficient awareness and biosecurity measures, although gE-deleted vaccines based on the Bartha-K61 strain and regional DIVA-based eradication programs have been widely used in the past decades. Notably, since 2011, an emerging variant PRV with enhanced pathogenicity has become prevalent in vaccinated swine herds in many regions of China and the disease situation is worsening. Control and eventual eradication of PR remain a big challenge in China, and strengthened control measures based on updated DIVA strategy are urgently needed toward national eradication of PR.


      PubDate: 2015-12-30T06:05:00Z
       
  • Novel triple-reassortant H1N1 swine influenza viruses in pigs in Tianjin,
           Northern China
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Ying-Feng Sun, Xiu-Hui Wang, Xiu-Li Li, Li Zhang, Hai-Hua Li, Chao Lu, Chun-Lei Yang, Jing Feng, Wei Han, Wei-Ke Ren, Xiang-Xue Tian, Guang-Zhi Tong, Feng Wen, Ze-Jun Li, Xiao-Qian Gong, Xiao-Min Liu, Bao-Yang Ruan, Ming-Hua Yan, Hai Yu
      Pigs are susceptible to both human and avian influenza viruses and therefore have been proposed to be mixing vessels for the generation of pandemic influenza viruses through reassortment. In this study, for the first time, we report the isolation and genetic analyses of three novel triple-reassortant H1N1 swine influenza viruses from pigs in Tianjin, Northern China. Phylogenetic analysis showed that these novel viruses contained genes from the 2009 pandemic H1N1 (PB2, PB1, PA and NP), Eurasian swine (HA, NA and M) and triple-reassortant swine (NS) lineages. This indicated that the reassortment among the 2009 pandemic H1N1, Eurasian swine and triple-reassortant swine influenza viruses had taken place in pigs in Tianjin and resulted in the generation of new viruses. Furthermore, three human-like H1N1, two classical swine H1N1 and two Eurasian swine H1N1 viruses were also isolated during the swine influenza virus surveillance from 2009 to 2013, which indicated that multiple genetic lineages of swine H1N1 viruses were co-circulating in the swine population in Tianjin, China. The emergence of novel triple-reassortant H1N1 swine influenza viruses may be a potential threat to human health and emphasizes the importance of further continuous surveillance.


      PubDate: 2015-12-26T05:59:21Z
       
  • Detailed chronological analysis of microevolution events in herds infected
           persistently by Mycobacterium bovis
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Yurena Navarro, Beatriz Romero, Emilio Bouza, Lucas Domínguez, Lucía de Juan, Darío García-de-Viedma
      Various studies have analyzed microevolution events leading to the emergence of clonal variants in human infections by Mycobacterium tuberculosis. However, microevolution events in animal tuberculosis remain unknown. We performed a systematic analysis of microevolution events in eight herds that were chronically infected by Mycobacterium bovis for more than 12 months. We analyzed 88 animals using a systematic screening procedure based on discriminatory MIRU-VNTR genotyping at sequential time points during the infection. Microevolution was detected in half of the herds studied. Emergence of clonal variants did not require long infection periods or a high number of infected animals in the herd. Microevolution was not restricted to strains from specific spoligotypes, and the subtle variations detected involved different MIRU loci. The genetic locations of the subtle genotypic variations recorded in the clonal variants indicated potential functional significance. This finding was consistent with the dynamics of some clonal variants, which outcompeted the original strains, suggesting an advantageous phenotype. Our data constitute a first step in defining the thresholds of variability to be tolerated in molecular epidemiology studies of M. bovis. We could therefore ensure that related clonal variants emerging as a result of microevolution events are not going to be misinterpreted as unrelated isolates.


      PubDate: 2015-12-26T05:59:21Z
       
  • Novel chimeric foot-and-mouth disease virus-like particles harboring
           serotype O VP1 protect guinea pigs against challenge
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Haitao Li, Zhiyong Li, Yinli Xie, Xiaodong Qin, Xingcai Qi, Peng Sun, Xingwen Bai, Youji Ma, Zhidong Zhang
      Foot-and-mouth disease is a highly contagious, acute viral disease of cloven-hoofed animal species causing severe economic losses worldwide. Among the seven serotypes of foot-and-mouth disease virus (FMDV), serotype O is predominant, but its viral capsid is more acid sensitive than other serotypes, making it more difficult to produce empty serotype O VLPs in the low pH insect hemolymph. Therefore, a novel chimeric virus-like particle (VLP)-based candidate vaccine for serotype O FMDV was developed and characterized in the present study. The chimeric VLPs were composed of antigenic VP1 from serotype O and segments of viral capsid proteins from serotype Asia1. These VLPs elicited significantly higher FMDV-specific antibody levels in immunized mice than did the inactivated vaccine. Furthermore, the chimeric VLPs protected guinea pigs from FMDV challenge with an efficacy similar to that of the inactivated vaccine. These results suggest that chimeric VLPs have the potential for use in vaccines against serotype O FMDV infection.


      PubDate: 2015-12-26T05:59:21Z
       
  • Detection of Staphylococcus aureus adhesion and biofilm-producing genes
           and their expression during internalization in bovine mammary epithelial
           cells
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Elizabet A.L. Pereyra, Florencia Picech, María S. Renna, Celina Baravalle, Carolina S. Andreotti, Romina Russi, Luis F. Calvinho, Cristina Diez, Bibiana E. Dallard
      Staphylococcus aureus is one of the most prevalent pathogens isolated from bovine mastitis, causing chronic intramammary infections (IMI) that limit profitable dairying. The course of infection is often associated with factors both related to the host and the bacterium. Aims of this study were to select S. aureus isolates from bovine IMI with different genotypic profiles harboring genes involved in adherence and biofilm production, to determine the behavior of these strains in contact with bovine mammary epithelial cells (MAC-T) and the expression of those genes during bacterial-cell early interactions. The genetic diversity of 20 S. aureus strains that were isolated from milk samples taken from cows with persistent-P and non-persistent-NP IMI was high, discriminated into 13 fingerprint groups. The occurrence of genes coding for S. aureus surface proteins (clfA, clfB, fnbA, fnbB, fib, cna) and biofilm formation (icaA, icaD, icaC, bap) and in vitro biofilm-forming ability was not related to strain clinical origin (NP or P). Internalization of S. aureus into MAC-T cells was strain-dependent and internalized bacteria overexpressed adherence and biofilm-forming genes compared with those that remained in the supernatant of co-cultures; particularly those genes encoding FnBPs and IcaD. Strains yielding highest invasion percentages were those able to overexpress fnBP, irrespectively of the presence of other evaluated genes. Strains from NP IMI showed a greater multiplication capacity in vitro compared with strains from P IMI. These results provide new insights about S. aureus differential gene expression of adhesion-internalization factors during early interaction with mammary epithelial cells.


      PubDate: 2015-12-22T05:47:13Z
       
  • Fatal nocardiosis in a dog caused by multiresistant Nocardia veterana
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Ann-Kathrin Uhde, Jochen Kilwinski, Martin Peters, Jutta Verspohl, Andrea T. Feßler, Stefan Schwarz, Peter Wohlsein
      Among pathogenic Nocardia species in humans and animals, infections caused by Nocardia (N.) veterana have rarely been described and so far, all non-human cases are linked to bovine mastitis in Brazil. The aim of this study was to identify the causative microorganism involved in the death of a three-month-old dog suffering from dyspnea and neurological deficits ante mortem. Pathomorphological investigation revealed (pyo-)granulomatous lesions in various organs. Bacteriological examination was performed and the respective bacteria were subjected to matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS), 16S rDNA sequencing, and antimicrobial susceptibility testing by broth microdilution. Gram-staining and colony morphology suggested the presence of an actinomycete which was identified as N. veterana by MALDI-TOF MS. This identification was confirmed by 16S rDNA sequence analysis. Distemper-associated immunosuppression may have played a role in the pathogenesis of systemic nocardiosis in this dog. Retrospective analysis of the antimicrobial susceptibility status showed that the N. veterana isolate was multiresistant and displayed high minimal inhibitory concentrations to all antimicrobial agents used for the dog’s therapy. To the best of our knowledge, this is the first report of a systemic nocardiosis caused by N. veterana in a dog with a concurrent canine distemper virus infection.


      PubDate: 2015-12-22T05:47:13Z
       
  • Investigation on host susceptibility of Tibetan pig to infection of
           porcine reproductive and respiratory syndrome virus through viral
           challenge study
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Runmin Kang, Gaosheng Ji, Xin Yang, Xuebing Lv, Yi Zhang, Mengyun Ge, Yun Pan, Qingzhou Li, Hongning Wang, Fanya Zeng
      Previous reports showed that infection of porcine reproductive and respiratory syndrome virus (PRRSV) stimulated a variable host response and pig susceptibility to PRRSV was largely dependent on its genetic composition. In the present study, host susceptibility of Tibetan pig to PRRSV was compared with other two pig breeds, ZangMei black and Large White, by challenge of them with highly pathogenic PRRSV (HP-PRRSV). In the first challenge test, each eight piglets of the three breeds were inoculated with HP-PRRSV and clinical symptoms, viremia and animal mortality were examined up to 28 days post inoculation (DPI). In the secondary pathological study, each twelve piglets of the three breeds were challenged and three pigs of each breed were sacrificed on 4, 7, and 14 DPI for examination of gross damage and lung microscopic lesions. The results showed that no typical clinical signs such as cough, diarrhea and high fever were observed in challenged Tibetan pigs, which however all occurred in Large White accompanied with ∼40% mortality (3/8). In addition, a significant low and short viremia was detected specifically in Tibetan pigs. Based on histopathological analysis of lung sections, a mild to moderate interstitial pneumonia in Tibetan pigs and a much severe pneumonia in Large White were identified on 7–14 DPI. In summary, the study demonstrated that three genetically different pig breeds exhibited a differential host susceptibility to HP-PRRSV and Tibetan pig was much less susceptible to the virus in the three tested pig breeds.


      PubDate: 2015-12-18T05:16:14Z
       
  • Phocine distemper virus (PDV) seroprevalence as predictor for future
           outbreaks in harbour seals
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Eva Ludes-Wehrmeister, Claudia Dupke, Timm C. Harder, Wolfgang Baumgärtner, Ludwig Haas, Jonas Teilmann, Rune Dietz, Lasse F. Jensen, Ursula Siebert
      Phocine distemper virus (PDV) infections caused the two most pronounced mass mortalities in marine mammals documented in the past century. During the two outbreaks, 23,000 and 30,000 harbour seals (Phoca vitulina), died in 1988/1989 and 2002 across populations in the Wadden Sea and adjacent waters, respectively. To follow the mechanism and development of disease spreading, the dynamics of Morbillivirus-specific antibodies in harbour seal populations in German and Danish waters were examined. 522 serum samples of free-ranging harbour seals of different ages were sampled between 1990 and 2014. By standard neutralisation assays, Morbillivirus-specific antibodies were detected, using either the PDV isolate 2558/Han 88 or the related canine distemper virus (CDV) strain Onderstepoort. A total of 159 (30.5%) of the harbour seals were seropositive. Annual seroprevalence rates showed an undulating course: Peaks were seen in the post-epidemic years 1990/1991 and 2002/2003. Following each PDV outbreak, seroprevalence decreased and six to eight years after the epidemics samples were tested seronegative, indicating that the populations are now again susceptible to new PDV outbreak. After the last outbreak in 2002, the populations grew steadily to an estimated maximum (since 1975) of about 39,100 individuals in the Wadden Sea in 2014 and about 23,540 harbour seals in the Kattegat area in 2013. A re-appearence of PDV would presumably result in another epizootic with high mortality rates as encountered in the previous outbreaks. The current high population density renders harbour seals vulnerable to rapid spread of infectious agents including PDV and the recently detected influenza A virus.


      PubDate: 2015-12-14T04:59:37Z
       
  • Reconstruction of the Schmallenberg virus epidemic in Belgium:
           Complementary use of disease surveillance approaches
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Antoine Poskin, Léonard Théron, Jean-Baptiste Hanon, Claude Saegerman, Muriel Vervaeke, Yves Van der Stede, Brigitte Cay, Nick De Regge
      Schmallenberg virus (SBV) emerged across Europe in 2011 and Belgium was among the first countries affected. In this study, published findings are combined with new data from veterinary surveillance networks and the Belgian reference laboratory for SBV at the Veterinary and Agrochemical Research centre (CODA-CERVA) to reconstruct the epidemic in Belgium. First retrospective cases of SBV were reported by veterinarians that observed decreased milk yield and fever in dairy cattle in May 2011. The number of SBV suspicions subsequently increased in adult cattle in August 2011. That month, first SBV positive pools of Culicoides were detected and extensive virus circulation occurred in Belgium during late summer and autumn 2011. As a consequence, most pregnant ruminants were infected and their fetuses exposed to the virus. This resulted in an outbreak of abortions, still-births and malformed new-borns observed between January and April 2012. The number of cases drastically diminished in 2012–2013, although multiple lines of evidence obtained from cross-sectional serological surveys, analyses on aborted foetuses, sentinel herd surveillance and surveillance of SBV in vectors prove that SBV was still circulating in Belgium at that time. Virus circulation was then probably strongly reduced in 2013–2014, while increasing evidence indicates its recirculation in 2014–2015 in Belgium. Based on the experience gathered with the closely related Akabane virus, recurrent outbreaks of congenital events can be expected for a long period. Vaccination of seronegative animals before the first mating could be used to prevent the deleterious effects of SBV. During this epidemic, different surveillance approaches including syndromic surveillance, sentinel herd surveillance, cross-sectional seroprevalence studies and pathogen surveillance in vectors have proven their utility and should be considered to continue in the future.


      PubDate: 2015-12-14T04:59:37Z
       
  • Epidemiological evolution of canine parvovirus in the Portuguese domestic
           dog population
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Carla Miranda, Colin R. Parrish, Gertrude Thompson
      Since its emergence, canine parvovirus type 2 (CPV-2) has caused disease pandemics with severe gastroenteritis signs, infecting especially puppies. As a consequence of CPV rapid evolution a variety of genetic and antigenic variants have been reported circulating worldwide. The detection of additional variants of CPV circulating in the dog population in Portugal suggests monitoring of the disease is useful. The objectives of this study were to further detect and characterize circulating field variants from suspected CPV diseased dogs that were admitted to veterinary clinics distributed throughout the country, during 2012–2014. Of the 260 fecal samples collected, 198 were CPV positive by PCR, and CPV antigen was detected in 61/109 samples by Immunochromatographic (IC) test. The restriction fragment length polymorphism (RFLP) analysis of 167 samples revealed that 86 were the CPV-2c. Sequence analysis of the 198 strains confirmed that CPV-2c were the dominant variant (51.5%), followed by CPV-2b (47.5%) and CPV-2a (1%). The variants were irregularly distributed throughout the country and some were detected with additional non-synonymous mutations in the VP2 gene. Phylogenetic analysis demonstrated that the isolates were similar to other European strains, and that this virus continues to evolve.


      PubDate: 2015-12-09T04:43:28Z
       
  • Ferret hepatitis E virus infection induces acute hepatitis and persistent
           infection in ferrets
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Tian-Cheng Li, Tingting Yang, Sayaka Yoshizaki, Yasushi Ami, Yuriko Suzaki, Koji Ishii, Noriko Kishida, Masayuki Shirakura, Hideki Asanuma, Naokazu Takeda, Takaji Wakita
      Ferret hepatitis E virus (HEV), a novel hepatitis E virus, has been identified in ferrets. However, the pathogenicity of ferret HEV remains unclear. In the present study, we compared the HEV RNA-positivity rates and alanine aminotransferase (ALT) levels of 63 ferrets between before and after import from the US to Japan. We found that the ferret HEV-RNA positivity rates were increased from 12.7% (8/63) to 60.3% (38/63), and ALT elevation was observed in 65.8% (25/38) of the ferret HEV RNA-positive ferrets, indicating that ferret HEV infection is responsible for liver damage. From long term-monitoring of ferret HEV infection we determined that this infection in ferrets exhibits three patterns: sub-clinical infection, acute hepatitis, and persistent infection. The ALT elevation was also observed in ferret HEV-infected ferrets in a primary infection experiment. These results indicate that the ferret HEV infection induced acute hepatitis and persistent infection in ferrets, suggesting that the ferrets are a candidate animal model for immunological as well as pathological studies of hepatitis E.


      PubDate: 2015-12-09T04:43:28Z
       
  • Effects of Rispens CVI988 vaccination followed by challenge with
           Marek’s disease viruses of differing virulence on the replication
           kinetics and shedding of the vaccine and challenge viruses
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Sithara Ralapanawe, Stephen W. Walkden-Brown, A.F.M. Fakhrul Islam, Katrin G. Renz
      Vaccination with “imperfect” vaccines that prevent disease but not infection is strongly implicated in the observed increased virulence of Marek’s disease virus (MDV) over the past six decades. The current “gold standard” vaccine, Rispens CVI988 (Rispens), has maintained efficacy despite use for five decades, raising the question of whether it too favours higher virulence MDVs. To investigate this, we studied the kinetics of Rispens CVI988 (Rispens) and two MDV strains of different virulence in 236 commercial ISA Brown chickens vaccinated with Rispens at hatch and challenged with vMDV isolate MPF57 or vvMDV isolate FT158 on day five. Each treatment was replicated in two isolators and from 7 to 56 days post infection (dpi) peripheral blood leucocytes (PBL), feather and dust samples were collected and subjected to differential quantitative PCR (qPCR). Rispens vaccination significantly reduced challenge MDV viral load in a sample-dependant manner with evidence of a differentially greater inhibitory effect on the less virulent MDV. Similarly, challenge with the more virulent MDV reduced the Rispens viral load in PBL. Rispens virus load displayed a distinctive pattern of viral load that was similar in PBL and feathers, but different in dust. The clear effects of vaccination and challenge evident in PBL and feather samples were less clearly reflected in dust samples. The data are consistent with the Rispens vaccine reducing replication of lesser virulent MDVs to a greater extent like the HVT vaccine. Likely reasons for the persistent efficacy of Rispens vaccine are discussed.


      PubDate: 2015-12-09T04:43:28Z
       
  • Outer membrane lipoprotein VacJ is required for the membrane integrity,
           
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Fang Xie, Gang Li, Wanjiang Zhang, Yanhe Zhang, Long Zhou, Shuanghong Liu, Siguo Liu, Chunlai Wang
      The outer membrane proteins of Actinobacillus pleuropneumoniae are mediators of infection, acting as targets for the host’s defense system. The outer membrane lipoprotein VacJ is involved in serum resistance and intercellular spreading in several pathogenic bacteria. To investigate the role of VacJ in the pathogenicity of Actinobacillus pleuropneumoniae, the vacJ gene-deletion mutant MD12 ΔvacJ was constructed. The increased susceptibility to KCl, SDS plus EDTA, and several antibiotics in the MD12ΔvacJ mutant suggested that the stability of the outer membrane was impaired as a result of the mutation in the vacJ gene. The increased NPN fluorescence and significant cellular morphological variation in the MD12ΔvacJ mutant further demonstrated the crucial role of the VacJ lipoprotein in maintaining the outer membrane integrity of A. pleuropneumoniae. In addition, the MD12ΔvacJ mutant exhibited decreased survival from the serum and complement killing compared to the wild-type strain. Interestingly, the MD12ΔvacJ mutant showed reduced biofilm formation compared to the wild-type strain. To our knowledge, this is the first description of the VacJ lipoprotein contributing to bacterial biofilm formation. The data presented in this study illustrate the important role of the VacJ lipoprotein in the maintenance of cellular integrity, serum resistance, and biofilm formation in A. pleuropneumoniae.


      PubDate: 2015-12-05T14:08:35Z
       
  • C-reactive protein, haptoglobin and Pig-Major acute phase protein profiles
           of pigs infected experimentally by different isolates of porcine
           reproductive and respiratory syndrome virus
    • Abstract: Publication date: 1 February 2016
      Source:Veterinary Microbiology, Volume 183
      Author(s): Y. Saco, F. Martínez-Lobo, M. Cortey, R. Pato, R. Peña, J. Segalés, C. Prieto, A. Bassols
      Porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) is the etiologic agent of PRRS, one of the most important diseases in swine worldwide. In the present work, the effects of different PRRSV strains were tested on a piglet experimental model to study the induced acute phase response. For this purpose, pigs (n =15 for each group) were intranasally inoculated with one of five PRRSV strains (isolates EU10, 12, 17, 18 from genotype 1 and isolate JA-142 from genotype 2). The acute phase response was monitored by measuring acute phase proteins (APPs). Specifically, the serum concentration of haptoglobin (Hp), C-reactive protein (CRP) and Pig-Major Acute Protein (Pig-MAP) was determined at 0, 3, 6, 9, 12, 15, 18 and 21 days p.i. Clinical signs and growth performance were also monitored during the experiment. All animals became viremic after inoculation during the study period. The APP response was heterogeneous and dependent on the strain, being strains EU10, EU 18 and JA-142 those that induced the highest response and the strongest clinical signs. In general, Hp was the most sensitive biomarker for PRRSV infection, CRP behaved as moderate and Pig-MAP was the less responsive during the course of PRRSV experimental infection. Hp and CRP were significantly discriminatory between infected and control pigs, but not Pig-MAP.


      PubDate: 2015-12-05T14:08:35Z
       
  • Experimental reproduction of beak atrophy and dwarfism syndrome by
           infection in cherry valley ducklings with a novel goose parvovirus-related
           parvovirus
    • Abstract: Publication date: Available online 30 November 2015
      Source:Veterinary Microbiology
      Author(s): Hao Chen, Yanguo Dou, Yi Tang, Xiaoqiang Zheng, Xiaoyu Niu, Jing Yang, Xianglong Yu, Youxiang Diao
      Infection of clinically susceptible ducks, including cherry valley and Muscovy ducks, with a novel goose parvovirus (GPV)-related virus (N-GPV) can result in beak atrophy and dwarfism syndrome (BADS). To obtain new insights into the host range and pathogenic potential of this novel waterfowl parvovirus, cherry valley ducklings (n =20) were experimentally infected with N-GPV strain SDLC01. An equal number of ducklings served as uninfected controls. The appearance of clinical signs, histopathological changes, viral shedding, and seroconversion was monitored for 20 days post-infection. Infection status of all ducks was monitored using indirect ELISA, virus neutralization test, nested PCR, clinical indicators, and microscopic examination. Three ducks developed the typical clinical, gross, and histological changes of BADS. By study day 6, the infected ducks had seroconverted to N-GPV. The antibodies raised were neutralizing against the SDLC01 strain in vitro. Here we successfully developed an experimental infection model for studying the pathogenicity and role of N-GPV in BADS.


      PubDate: 2015-12-01T13:47:42Z
       
 
 
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